1. Field of the Invention
The present invention relates to a vacuum treatment apparatus for a surface treating of substrates or workpieces. It also relates to a vacuum treatment apparatus having a valve for a sealed closing off of the apparatus. It relates further to a method of treating substrates or workpieces by means of a vacuum treatment apparatus. It relates also to a valve for a sealed separating and, furthermore, to a method of a sealed closing or separating, of a vacuum treatment plant or area portions thereof.
2. Description of the Prior Art
For the treatment of workpieces specific operating pressures are required in a vacuum chamber depending from the respective vacuum process to be performed. When workpieces are placed from the environment into the vacuum chamber, or from a treatment chamber into a different one, partition members which seal off must be foreseen. To this end, as is known, doors, valves or entire lock devices, resp. are foreseen.
When conducting a plurality of parallel treatment steps in vacuum processing apparatuses (e.g. multi-layer coatings) it is often necessary to separate the processing chambers from each other during the conducting of the processes. This is generally arrived at by a use of separating valves. In order to transport the substrates from one chamber into a subsequent chamber the separating valves are opened and the workpieces are advanced by one respective step by transporting units. These transporting units must have left the area of the opening of the valves before the closing or activating, resp. of the separating valves in order to allow a sealed separating of the respective process chambers. This leads firstly to a loss of precious time and secondly the transporting system must consist of a plurality of unit portions due to the problem of the penetration.
An attempt to solve this problem is described in the European specification EP-A-O 370 188 in that a transporting unit is suggested which considerably simplifies and accelerates the charging and the emptying of a process chamber. The basic principle consists in that the transporting device is formed of respective lever devices pivotally supported in the process chambers and which reach through the opened slot-shaped valves.
A further solution consists in that the article to be treated is introduced by a transporting mechanism in such a manner into the processing chamber that the chamber is closed off ,in a sealed manner by the mechanism itself and the movement in the direction towards the chamber such to allow the running of the process.
In a similar manner the European specification EP-A-O 244 950 describes a multiple-surface treatment apparatus for the treatment of planar articles, such as e.g. wafers, where these articles are transported on a moveable or rotatable, support between several operating stations in the apparatus. At the respective stations sealing means on the support are brought to engage corresponding sealing means at a treatment chamber in that congruent contours having seals and arranged at the support and at the treatment chamber contact each other and, therefore, can separate the chamber containing the respective substrate to be treated from the environment in a sealed manner.
Further variants of apparatuses for the treatment of substrates or the production, resp. of thin coatings are suggested in the German specifications DE 24 54 544, DE 26 09 115, DE 24 20 439, DE 40 09 603, DE 37 16 498, DE 37 35 284, DE 39 12 297, DE 39 12 295 and in the US-PS 3 874 525.
A vacuum treatment plant having a plurality of treatment stations is described in the DE-A-34 25 267, whereby a specially designed transport system is foreseen which includes a vertical and a horizontal transporting means. The isulation of the individual stations from the main chamber proceeds again in that sealing means are foreseen at a vertical transporting means, which separate the treatment chamber in a sealed manner when the substrate to be treated is introduced into the treatment chamber.
Common to all described apparatuses is that substrate supports or the substrates themselves are led or transported, by means of a transporting means into one or a plurality of treatment chambers in order to be surface treated at a vacuum in the one chamber or several chambers. Aside of these transporting means at least one further transporting or moving, mechanism is needed in order to cause a mutual engaging of sealing means in the treatment chamber or the one or several treatment chambers and corresponding sealing means, for instance at the substrate itself or at a support on which the substrate is transported, such that the chamber or the chambers can be closed in a sealed manner for the conducting of a treatment process. At the one side, such a contacting or engaging of the sealing means must be a precise fitting onto each other such to ensure a good seal, and additionally mentioned transporting or moving, means and mechanisms are sources of a possible contamination in these chambers, except when the various transporting mechanisms are separated by means of intrinsic bellows systems from the inside space of the apparatus or the chambers, in order to prevent contaminations.